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Background: In circumpolar countries such as Canada,northern regions represent a unique geographical entity climatically, socioeconomically and environmentally.There is a lack of comparative data on birth outcomes among Indigenous and non-Indigenous subpopulations within northern regions and compared with southern regions.Methods: A cohort study of all births by maternal mother tongue to residents of northern (2616 First Nations(North American Indians), 2388 Inuit and 5006 non-Indigenous) and southern (2563 First Nations, 810 643non-Indigenous) Quebec, 1991-2000.Results: Compared with births to southern non-Indigenous mother tongue women, births to northern women of all three mother tongue groups were at substantially elevated risks of infant death (adjusted OR (aOR) 1.7-2.9), especially post neonatal death (aOR2.2-4.4) after controlling for maternal education, age,marital status and parity. The risk elevation in perinatal death was greater for southern First Nations (aOR 1.6)than for northern First Nations (aOR 1.2). Infant macrosomia was highly prevalent among First Nations in Quebec, especially in the north (31% vs 24% in the south). Within northern regions, Inuit births were at highest risk of preterm delivery (aOR 1.4) and infant death (aOR 1.6).Conclusion: All northern infants (First Nations, Inuit or non-Indigenous) were at substantially elevated risk of infant death in Quebec, despite a universal health insurance system. Southern First Nations newborns have not benefited from the more advanced perinatal care facilities in southern regions. Environmental influences may partly account for the very high prevalence of macrosomia among First Nations in northern Quebec. [ABSTRACT FROM AUTHOR]

Background: Maternal socioeconomic status (SES) is an important determinant of inequity in maternal and fetal health. We sought to determine the extent to which associations between adverse birth outcomes and SES can be identified using individual-level measures (maternal level of education) and community-level measures (neighbourhood income). Methods: In Quebec, the birth registration form includes a field for the mother's years of education. Using data from birth registration certificates, we identified all births from 1991 to 2000. Using maternal postal codes that can be linked to census enumeration areas, we determined neighbourhood income levels that reflect SES. Results: Lower levels of both maternal education and neighbourhood income were associated with elevated crude risks of preterm birth, small-for-gestational-age (SGA) birth, still-birth and neonatal and postneonatal death. The effects of maternal education were stronger than, and independent of, those of neighbourhood income. Compared with women in the highest neighbourhood income quintile, women in the lowest quintile were significantly more likely to have a preterm birth (adjusted odds ratio [OR] 1.14, 95% confidence interval [CI] 1.10-1.17), SGA birth (OR 1.18, 95% CI 1.15-1.21) or stillbirth (OR 1.30, 95% CI 1.13-1.48); compared with mothers who had completed community college or at least some university, mothers who had not completed high school were significantly more likely to have a preterm birth (adjusted OR 1.48, 95% CI 1.44-1.52), SGA birth (OR 1.86, 95% CI 1.82-1.91) or stillbirth (OR 1.54, 95% CI 1.36-1.74). Interpretation: Individual and, to a lesser extent, neighbourhood-level SES measures are independent indicators for subpopulations at risk of adverse birth outcomes. Women with lower education levels and those living in poorer neighbourhoods are more vulnerable to adverse birth outcomes and may benefit from heightened clinical vigilance and counselling. [ABSTRACT FROM AUTHOR]

We used Statistics Canada's linked stillbirth, live birth and infant death files to assess the risks of adverse pregnancy outcomes among Inuit and North American Indian vs. other ethnic women in Quebec, 1985–97 (1 125 462 singleton births). Mother tongue was used to define ethnicity, with the largest French language group as the reference. Main outcome measures are adjusted odds ratios (AOR) for preterm birth, small-for-gestational-age (SGA), stillbirth, neonatal and postneonatal death controlled for maternal age, education, marital status, parity, infant sex, community size, and community-level random effects using multilevel logit models. Inuit women had higher risks of preterm birth (AOR = 1.49, 95% CI [1.25, 1.78]) and immaturity-related infant mortality (AOR = 3.03 [1.36, 6.74]), while Indian women did not. Infants of Inuit (AOR = 0.39 [0.31, 0.49]) and Indian (AOR = 0.27 [0.24, 0.31]) women had substantially lower risks of SGA. Elevated risks of stillbirth were observed among Indian women [AOR = 1.53 (1.09, 2.15)], and of postneonatal death among both Inuit (AOR = 4.45 [2.74, 7.22]) and Indian (AOR = 1.86 [1.28, 2.70]) infants. Both Inuit and Indian infants had much higher risks of sudden infant death syndrome (SIDS) and infection-related mortality. Although the absolute risks of adverse outcomes declined from 1985–87 to 1995–97, the relative disparities between aboriginal and non-aboriginal women changed little over this period. We conclude that Inuit and Indian women have different risk profiles for adverse pregnancy outcomes, and that prevention of preterm birth among Inuit women, and of SIDS and infection-related infant mortality in both aboriginal groups, are important targets for future research and intervention. [ABSTRACT FROM AUTHOR]

Background: Cree births in Quebec are characterized by the highest reported prevalence of macrosomia (~35%) in the world. It is unclear whether Cree births are at greater elevated risk of perinatal and infant mortality than other First Nations relative to non-Aboriginal births in Quebec, and if macrosomia may be related. Methods: This was a population-based retrospective birth cohort study using the linked birth-infant death database for singleton births to mothers from Cree (n = 5,340), other First Nations (n = 10,810) and non-Aboriginal (n = 229,960) communities in Quebec, 1996–2010. Community type was ascertained by residential postal code and municipality name. The primary outcomes were perinatal and infant mortality. Results: Macrosomia (birth weight for gestational age >90th percentile) was substantially more frequent in Cree (38.0%) and other First Nations (21.9%) vs non-Aboriginal (9.4%) communities. Comparing Cree and other First Nations vs non-Aboriginal communities, perinatal mortality rates were 1.52 (95% confidence intervals 1.17, 1.98) and 1.34 (1.10, 1.64) times higher, and infant mortality rates 2.27 (1.71, 3.02) and 1.49 (1.16, 1.91) times higher, respectively. The risk elevations in perinatal and infant death in Cree communities attenuated after adjusting for maternal characteristics (age, education, marital status, parity), but became greater after further adjustment for birth weight (small, appropriate, or large for gestational age). Conclusions: Cree communities had greater risk elevations in perinatal and infant mortality than other First Nations relative to non-Aboriginal communities in Quebec. High prevalence of macrosomia did not explain the elevated risk of perinatal and infant mortality in Cree communities. [ABSTRACT FROM AUTHOR]

Background: Aboriginal populations are at substantially higher risks of adverse birth outcomes, perinatal and infant mortality than their non-Aboriginal counterparts even in developed countries including Australia, U.S. and Canada. There is a lack of data on recent trends in Canada. Methods: We conducted a population-based retrospective cohort study (n = 254,410) using the linked vital events registry databases for singleton births in Quebec 1996–2010. Aboriginal (First Nations, Inuit) births were identified by mother tongue, place of residence and Indian Registration System membership. Outcomes included preterm birth, small-for-gestational-age, large-for-gestational-age, low birth weight, high birth weight, stillbirth, neonatal death, postneonatal death, perinatal death and infant death. Results: Perinatal and infant mortality rates were 1.47 and 1.80 times higher in First Nations (10.1 and 7.3 per 1000, respectively), and 2.37 and 4.46 times higher in Inuit (16.3 and 18.1 per 1000, respectively) relative to non-Aboriginal (6.9 and 4.1 per 1000, respectively) births (all p<0.001). Compared to non-Aboriginal births, preterm birth rates were persistently (1.7–1.8 times) higher in Inuit, large-for-gestational-age birth rates were persistently (2.7–3.0 times) higher in First Nations births over the study period. Between 1996–2000 and 2006–2010, as compared to non-Aboriginal infants, the relative risk disparities increased for infant mortality (from 4.10 to 5.19 times) in Inuit, and for postneonatal mortality in Inuit (from 6.97 to 12.33 times) or First Nations (from 3.76 to 4.25 times) infants. Adjusting for maternal characteristics (age, marital status, parity, education and rural vs. urban residence) attenuated the risk differences, but significantly elevated risks remained in both Inuit and First Nations births for the risks of perinatal mortality (1.70 and 1.28 times, respectively), infant mortality (3.66 and 1.47 times, respectively) and postneonatal mortality (6.01 and 2.28 times, respectively) in Inuit and First Nations infants (all p<0.001). Conclusions: Aboriginal vs. non-Aboriginal disparities in adverse birth outcomes, perinatal and infant mortality are persistent or worsening over the recent decade in Quebec, strongly suggesting the needs for interventions to improve perinatal and infant health in Aboriginal populations, and for monitoring the trends in other regions in Canada. [ABSTRACT FROM AUTHOR]

Background: Inuit and First Nations populations have higher rates of stillbirth than non- Aboriginal populations in Canada do, but little is known about the timing and cause of stillbirth in Aboriginal populations. We compared gestational age- and cause-specific stillbirth rates in Inuit and First Nations populations with the rates in the non-Aboriginal population in Quebec. Methods: Data included singleton stillbirths and live births at 24 or more gestational weeks among Quebec residents from 1981 to 2009. We calculated odds ratios (ORs), rate differences and 95% confidence intervals (CIs) for the retrospective cohort of Inuit and First Nations births relative to non-Aboriginal births using fetuses at risk (i.e., ongoing pregnancies) as denominators and adjusting for maternal characteristics. The main outcomes were stillbirth by gestational age (24-27, 28- 36, ⩾ 37 wk) and cause of death. Results: Rates of stillbirth per 1000 births were greater among Inuit (6.8) and First Nations (5.7) than among non-Aboriginal (3.6) residents. Relative to the non- Aboriginal population, the risk of stillbirth was greater at term (⩾ 37 wk) than before term for both Inuit (OR 3.1, 95% CI 1.9 to 4.8) and First Nations (OR 2.6, 95% CI 2.1 to 3.3) populations. Causes most strongly associated with stillbirth were poor fetal growth, placental disorders and congenital anomalies among the Inuit, and hypertension and diabetes among the First Nations residents. Interpretation: Stillbirth rates in Aboriginal populations were particularly high at term gestation. Poor fetal growth, placental disorders and congenital anomalies were important causes of stillbirth among the Inuit, and diabetic and hypertensive complications were important causes in the First Nations population. Prevention may require improvements in pregnancy and obstetric care. [ABSTRACT FROM AUTHOR]

Background: High prevalence of infant macrosomia (up to 36%, the highest in the world) has been reported in some First Nations communities in the Canadian province of Quebec and the eastern area of the province of Ontario. We aimed to assess whether infant macrosomia was associated with elevated risks of perinatal and postneonatal mortality among First Nations people in Quebec. Methods: We calculated risk ratios (RRs) of perinatal and postneonatal mortality by birthweight for gestational age, comparing births to First Nations women (n = 5193) versus women whose mother tongue is French (n = 653 424, the majority reference group) in Quebec 1991-2000. Results: The prevalence of infant macrosomia (birthweight for gestational age > 90th percentile) was 27.5% among births to First Nations women, which was 3.3 times (confidence interval [CI] 3.2-3.5) higher than the prevalence (8.3%) among births to women whose mother tongue is French. Risk ratios for perinatal mortality among births to First Nations women were 1.8 (95% CI 1.3-2.5) for births with weight appropriate for gestational age, 4.1 (95% CI 2.4-7.0) for small-for-gestational- age (< 10th percentile) births and < 1 (not significant) for macrosomic births compared to births among women whose mother tongue is French. The RRs for postneonatal mortality were 4.3 (95% CI 2.7-6.7) for infants with appropriate-for-gestational-age birthweight and 8.3 (95% CI 4.0-17.0) for infants with macrosomia. Interpretation: Macrosomia was associated with a generally protective effect against perinatal death, but substantially greater risks of postneonatal death among births to First Nations women in Quebec versus women whose mother tongue is French. [ABSTRACT FROM AUTHOR]

Objective: To examine the effects of tea consumption during pregnancy on the risk of pre-eclampsia.Methods: A case-control study was carried out among nulliparous pregnant women in Quebec between January 2003 and March 2006. Data were collected using a structured study questionnaire. A total of 92 women with pre-eclampsia and 245 controls were analyzed. Univariate analysis and multivariate regression were performed to examine the association between tea consumption and pre-eclampsia.Results: Compared with non-tea drinking during pregnancy, the crude odds ratio (OR) and adjusted OR (aOR) of pre-eclampsia for tea drinking were 1.34 (95% CI, 0.80-2.25) and 1.39 (95% CI, 0.81-2.41), respectively. The OR and aOR of severe pre-eclampsia for tea drinking were 1.39 (95% CI, 0.78-2.46) and 2.14 (95% CI, 1.01-4.54), respectively. The aORs for persistent tea consumption in pre-eclampsia and severe pre-eclampsia were 1.88 (95% CI, 1.01-3.51) and 1.95 (95% CI, 1.06-3.57), respectively.Conclusion: Persistent tea drinking during pregnancy may be associated with an increased risk of pre-eclampsia. [ABSTRACT FROM AUTHOR]

Background: Interpregnancy interval (IPI), marital status, and neighborhood are independently associated with birth outcomes. The joint contribution of these exposures has not been evaluated. We tested for effect modification between IPI and marriage, controlling for neighborhood. Methods: We analyzed a cohort of 98,330 live births in Montréal, Canada from 1997-2001 to assess IPI and marital status in relation to small for gestational age (SGA) birth. Births were categorized as subsequent-born with short (<12 months), intermediate (12-35 months), or long (36+ months) IPI, or as firstborn. The data had a 2-level hierarchical structure, with births nested in 49 neighborhoods. We used multilevel logistic regression to obtain adjusted effect estimates. Results: Marital status modified the association between IPI and SGA birth. Being unmarried relative to married was associated with SGA birth for all IPI categories, particularly for subsequent births with short (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.31-1.95) and intermediate (OR 1.48, 95% CI 1.26-1.74) IPIs. Subsequent births had a lower likelihood of SGA birth than firstborns. Intermediate IPIs were more protective for married (OR 0.50, 95% CI 0.47-0.54) than unmarried mothers (OR 0.65, 95% CI 0.56-0.76). Conclusion: Being unmarried increases the likelihood of SGA birth as the IPI shortens, and the protective effect of intermediate IPIs is reduced in unmarried mothers. Marital status should be considered in recommending particular IPIs as an intervention to improve birth outcomes. [ABSTRACT FROM AUTHOR]